Page 290 - Praxair - Specialty Gases and Equipment Reference Guide

9000 Gas Delivery System

Dewar Changeover System

™
ProSpec Series 9000 Automatic
Dewar Changeover System
The Series 9000 Automatic Dewar Changeover System is
designed to provide an uninterrupted flow of gas from one of
two sources. When one source is in service providing the gas
to process; the other source is on standby, and comes on-line
when the current source has depleted. The changeover to the
standby source occurs automatically. Once the changeover has
occurred, a gas technician replaces the depleted source, turns
the changeover regulator hand knob to the next standby source.
The Series 9000 system employs a unique Tri-Block design,
which incorporates dual back pressure regulators and a line
regulator. This Tri-Block assembly functions as an economizer
circuit, to prevent venting of the reserve source.
The Series 9000 system includes a line regulator to allow
adjustment of the final delivery pressure to the process. Also
included are 6' stainless steel armor-jacketed flexible pigtails,
with CGA check valves, cylinder isolation and vent valves. This
configuration gives the operator the capability to isolate a source
from the changeover panel, allowing replacement of the source
without having to shut down the system.

Features and Benefits
n Integral Line Regulator n User Friendly Priority Valve
Constant delivery pressure Single lever operation Section E – Gas Handling Equipment
n 6' Stainless steel pigtails n Check Valves
Easy cylinder connections Helps prevent backflow
n Preset Dual Back Pressure n Automatic Changeover
Regulators Continuous gas supply
Allows gas flow to enter the
process piping n Panel Mounted
Easy installation

Specifications Materials
n Maximum Inlet Pressure n Bodies
400 psig Brass Barstock
n Outlet Pressure Range n Diaphragms
0-100 psig 316L Ordering Information – Series PRS9000
n Maximum flow @ n Seats/Seals Series Model A B C
80 psig outlet PTFE Number (Number of Dewars) (Options) (CGA)
25 slpm
PRS 9000 1: 1 x 1 1: No Alarm 580
n Temperature Range 2: 2 x 2 2: Audio/Visual 320
-40 °F to 148 °F 3: 3 x 3 540
n Gauges
2-1/2"
Example Part Number
PRS9000-11580 = Basic changeover for
two dewars, no alarm and CGA 580

Serial
Number A C

s
s
s
PRS9000-11580
s s
Model B

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